Method of treating hydrocarbon oil



Sept. 1, 1936. H. R. sNo w- METHOD OF TREATING HYDROCARBON OIL Filed July 25, 1935 M WAY/MW mNl.

kWh NI INVENTOR ATTORNEY Patented Sept. 1, 1936 This invention relates to PATENT OFFICE lVlETHOD OF TREATING HYDROCABBON OIL Harold It. Snow,

Standard Oil Company, 111., a corporation of Indiana Neodesha, Kans., assignor to (Indiana), Chicago,

Application July 25, 1933, Serial No. 682,045

9 Claims.

slurries of lime in oil, particularly dered calcium hydroxide,

commonly methods for forming in hydrocarbon oil which is to be subjected to distillamix powcalled hydrated lime, with hydrocarbon oil which is to be cracked to form lig tion has also been made, lime-oil slurry, tity of water pension and drated lime has been added to oil which is cracked, with ing any acids pre 15 and/ or rosion of mixture. or to cause stabilization o from the oil. The

the intention of the distilling or of hydrated lime in oil, whereby the be rendered more stable with respect to settling.

A further object of my invention is hter products. The suggesto add to the hydrated suspension, 8. quanf the susretard the settling out of the hyhydrated lime to be distilled neutralizsent, thereby to reduce corcracking equipment, and also to aid in the filtering of a in the process.

It is an object of my improved process for ny tar formed invention to provide an the production of a slurry slurry will to provide be formed of caloil, and

water, the quicklime being hydrated in the presence of the oil.

In accordance with and water are mixed with a quantity quicklime together in rate as to insure ture shall not rise above water, as aresult of the hydration of the quicklime. and water may another in the presence tities than that low temperature and pos plied to counteract the quicklime may my invention and water preferably being the presence of the oil at such alow that the temperature of the mixthe boiling point of the heating attending the Or the the excessive quicklime of oil, the brought quicklime be brought into contact with one of the oil in larger quanwhich would result in the desired itive cooling may be supheating. While he added to the oil first and be thoroughly agitated, and then the water added subsequently, I prefer first to mix oil and then to add ture while providing a latter method produces a more and water the quicklime slowly to the mixgitation. I find that this stable slurry, that is, a slurry in which there is less tendency for tities alternatively. For example, at

part of 55 drate the the water necessary hydrated quicklime to settle out of When using this preferable to add to the in relatively small quancompletely to hyquicklime is mixed with the oil, then a portion of the quicklime is added, followed by the rest of the water necessary, and finally the remaining quicklime necessary to supply the total amount needed. In aspecific instance one-half of the water necessary may be mixed. with the oil, and then about on -third of the quicklime, followed by the other one-half of the water and the rest of the quicklime in the order mentioned. The quicklime may be employed in any degree of fineness, but I prefer to use it in very fine form, for example sufficiently fine to pass through a 200 mesh sieve, air floated quicklime being particularly suitable.

By utilizing this process several advantages are obtained, one being that the slurry formed is much more stable than that which it is pos-' sible to obtain according to known processes, when using previously hydrated lime to form the mixture. I have found that a slurry made by'hydrating quicklime while in mixture with the oil, the quicklime being first mixed with the oil and the water later added, produces a slurry more stable than that formed by the admixture with the oil of previously hydrated lime and water, but that the slurry made by first mixing water with the oil and then adding the quicklime is even more stable and desirable.

- The above mentioned and further objects and advantages of my invention, and the manner of attaining them will be more fully explained in the following description taken in conjunction with the accompanying drawing.

The drawing is a oil treating system embodying my invention. Referring more particularly to the drawing, reference numeral l indicates a tank or chamber, having leading thereinto a pipe 2, which connects to lime-hopper 3. This pipe has therein a control valve 4. The tank I also has a water inlet pipe 5, equipped with valve 6, a valved draw-ofi pipe I, a valved agitating fiuid inlet line 8, which connects with a distributing manifold 9 located inside of the tank, and a vent diagrammatical view of an line 35. Reference numeral l0 indicates an oil thoroughly agitated by the example it this, quicklime from the hopper 3 is passed through pipe 2 into the tank I, at a relatively low rate of flow, which is controlled by valve 4. The admission of this quicklime is preferably carried on at such a low rate that the temperature of the mixture in the tank i does not rise, due to the heat of hydration of the quicklime, to a value great enough to vaporize any considerable portion of the water. Preferably, this temperature is prevented from exceeding a value of about F. The rate of addition of the quicklime to the mixture may be increased, however, if at the same time a cooling fluid is passed through the indirect cooling coil l2 located inside of the tank, the cooling so supplied then serving to counteract the heat liberated as a result of hydration.

In carrying out this process I prefer first to add to the oil in the tank only a portion of the amount of water known to be necessary for the hydration of the quantity of quicklime to be added. This may be, for example, one-half of the water necessary. Then all or part of the total quantity of quicklime desired for the final mixture is added; preferably however, only a portion of the total amount of quicklime is added e. g. one-third thereof. Next an additional amount of water is introduced into the mixture, this amount preferably being the rest of the water necessary to make up the total amount, and finally any remaining quicklime is added. During all of these steps the mixture is preferably agitated in order to insure mingling of the several components, and the rate of commingling of the quicklime and water is kept relatively low to prevent-overheating, or suflicient cooling is provided by coil ii to maintain the desired low temperature. When steam is used as an agitating medium it will also aid in hydrating the quicklime, thereby serving as a source of water supply.

The lime-oil slurry formed may be withdrawn through line 1, to slurry supply tank l3, which provides additional reaction time for the slurry, and insures complete hydration of the lime; if such action is not fully obtained in the agitator I.

The completely formed slurry may be withdrawn from tank l3, forany desired use. For may be forced through line H, under pressure of pump l5, into line IS, in mixture with any desired quantities of charging oil, and thence to a cracking unit of any conventional design, indicated generally by reference numeral II. The mixture of slurry and charging oil passes through cracking heater I8, wherein the mixture is raised to a cracking temperature, and thence through transfer line l9 into still 20, wherein separation of liquids from vapors takes place. The vapors travel through vapor line 2| into fractionator 22, wherein desired relatively light products, such as gasoline, are separated as vapors, which pass oil through pipe 23 and condenser 24 into receiver 25. Undesirably heavy fractions are collected in the fractionator as reflux condensate, and may be withdrawn therefrom through line 26, either for recycling through conduit 21, by action of pump 28 or for diversion from the process through pipe 29. The liquid residue or tar separated in chamber 20 may be withdrawn through line 34, for filtering or any desired treatment.

The fresh charge for the cracking process, which may be gas oil or any other conventional charging stock, may be forced through heat exchange coil IZ, to cool the slurry and thereby counteract the heat the desired degree,

itself preheated, or may be directed wholly or in part through bypass pipe 3|, into line l6. Valves 32 and 33 provide the necessary control. Alternatively all or part of the cooling may be effected by passing other cooling fiuid, such as water, through heat exchange coil l2. H desired, the slurry may be so prepared in the agitator as to have the proper consistency for l racking without the addition of charging stock 1 :ereto. Reference numeral 36 indicates a drawoff line by which slurry may be diverted from the process.

In practical operation the amount of lime to be suspended in the oil may vary considerably depending upon the use to which the oil lime slurry is to be put. I find that where the slurry is to be used for admixture with other hydrocarbon oils for cracking in the usual manner, one and three-fourths to two pounds of quicklime may be a greater or lesser amountmay be used if desired. The amount of water used is preferably somewhat in excess of that actually necessary to accomplish the hydration of the quicklime. The total amount of water added, may be, for example, about 9% or' more by volume, of the oil.

A successful practical operation was conducted in the following manner:

First 4050 gallons of 24 A. P. I. gravity, distillate from cracked tar were pumped into the mixing tank, and gallons of water were added. After agitation of the water and oil air-floated quicklime was added slowly in order that the temperature be kept below 185 F., 250 pounds of quicklime being thus added. Next 190 gallons more of water was supplied, this making the total amount of water added. The mixture was then agitated and subsequently thereto more quicklime was added until a total of 7400 pounds was mixed into the batch. The maximum temperature reached was 183 E, and the time consumed in making this batch was approximately 40 hours. A titration test showed the content oi Ca(OH)2, by'weight, to be 21.6%.

A settling test carried out on this mixture indicated that at the separated from the slurry.

A slurry formed in accordance with the preceding description may be used for any desired pur- While I have described a particular embodiment of my invention for the purpose of illustration, it should be understood that various modifications and adaptations thereof, occurring to one added per gallon of oil, although skilled in the art, may be made within the spirit or the invention as set forth in the appended claims.

I claim:

LAmethodoimakinsalimeinoilsiurry which comprises first mixing water with a hydrocarbon oil to form a uniform mixture, then adding to said mixture iineLv divided quicklime to be hydrated by said water in the presence of said oil. 1

2. A process in accordance with claim 1 wherein the amount of quicklime so added is insufiicient to utilize all of said water in completing hydration oi'said quicklime.

pleteiy to hydrate the 3. A process according to claim 1 wherein during the addition or the quicklime to the oiland water mixture, a cooling medium i brought into heat exchange relation with said mixture, to prevent the temperature thereof mm rising due to the heat of hydration, suiiiciently to cause any considerable loss oi said water by vaporization. 4'. A process according to claim 1 wherein during the addition of the quicklime the temperature of the mixture is. prevented from exceeding a value of about 210 F.

5. A process according to claim 1 wherein during the addition of the quicklime the temperature or the mixture is held at a top value or about 180 F. Y Y

6. The process of forming a slurry of oil and lime which comprises mixing with said oil a quantity oi water less than that necessary comquickiime which is to be added, then adding to the mixture approximately one-third of the necessary quicklime. in airfloated iorm, then adding the remainder of the water necessary and Molly admixing the remainder oi the quickiime, in air-floated form, and during the process agitating the oil mixture and preventing the temperature thereof from exceeding a value of about 185 F.

7. A method of increasing the stability of a lime in oil slurry which comprises mixing water with hydrocarbon oiljand subsequently adding quicklime in an amount sufllcient to be completely hydrated by the water added.

8. A method of making a slurry of lime and petroleum oil as a final product of the process which consists in mixing water and quicklime with petroleum oil in a" common zone, maintaining said zone at a temperature which will avoid distillation of the materials being admixed therein, the amount of water being in excess of that necessary to hydrate the quicklime while in mixture with the oil and withdrawing said slurry from said zone.

9. The process of forminga slurry oi lime in petroleum oil as anen'd product of the process which consists in mixing quicklimc. water and petroleum oil in a mixing zone, maintaining said zone at a temperature which will avoid distillation of the material being mixed therein, so that the hydration of the quicklime is accomplished while in direct contact with the petroleum oil and 30 withdrawing said slurry from said zone as a product of the process.

HAROLD R. SNOW. 

